In the field of language endangerment, a common estimate is that half of the languages living today will fall silent in this century (or over the next 100 years).
The Ethnologue counts 6,909 languages living today, and 7,000 is also a common estimate of the number of languages currently spoken.
Yet a third estimate is that a language falls silent every 14 days. But 100 years multiplied by 365 days per year and divided by 14 results in 2,607 languages.
So if 3,500 languages will die over the next 100 years, how many days is that on average? Dividing 3,500 languages by 100 years yields 35 languages per year, and dividing 365 (days/year) by 35 languages yields 10.43 days.
Given the rapid increase in efforts to stabilize and revitalize languages, there is hope that neither the 14-day or 10.43-day estimate will come true, but even so, both are averages and languages will not die in an even manner. Rather, language silence will occur in uneven clumps.
Admittedly, though, citing one language as dying every 14 days makes for good press.